I was looking under my car today and found this thing on the exahust:
What is it?
Is this normal?

 

Helmholtz resonator, comes on all OEM exhaust.

 

so it makes the exhaust lighter?
If its cut off, it's will just get louder, or does is enhance performance?

 

It's there to reduce the droning from XX RPM's, I'm not sure what the RPM range is. Not sure what would happen if you cut it off, but I' would think it would get louder and it may free up the exhaust flow a bit.

 

It stops the exhaust from droning nasty sounds!

 

I bought the car used so i thought the guy cut something. for the dual exhaust. I even checked if both mufflers were connected.

anyways thanks

 

so has anyone cut this off or has everyone left it? i got a welder and plasma cutter and aint worried to find out the effects

 

without it you would get some droning and that's about it.

It certainly would NOT free up exhaust flow. Exhaust doesn't follow a torturous path into and out of the resonator. The resonator really just shifts the phase of sound waves to stop the droning. In some cases, as in air intakes, those waves are "said" to help airflow.

Helmholtz was a mathematician (and later a medical doctor). He understood how to avoid the resonance of an equation by preventing the denominator from becoming 0. This skill served him as Napoleon ordered him to help design gun barrels. Helmholtz worked with Laplace and Fourier. Today we have them to thank for the Laplace and Fourier transforms which help us EE guys.

Anyway, cut it off and you will drone during a certain RPM band. Short and sweet.

 

i have the same stubby on my amuse r1 titan also...

 

its normal